You can enable RX and adjust VOLUME and SQUELCH into your liking.
Sadly enough, you will NOT be able to use VOICE ACTIVATION when RX is enabled (to ensure there will be NO audio feedback defeating the VA sensing)
A "bug" that won over me, but perhaps and hopefully other coder can easily fix: The Vumeter will momentarily "dissappear" when enabling RX. But it will reappear as soon as you start TX. Or when you turn off RX.
I enabled the PEAK LEVEL MARK on the Vumeter, so you can easily see in which level your input voice / signal is peaking and regulate the MIC gain accordingly in an easier / more robust way.
Side enhancement: Took off the dark green, yellow and red coloring from the vumeter when no signal is present, and replaced it with dark_grey. I know that some coloring is "eye-candy" but the vu-meter is more readable with this new contrast.
* ui_transmitter : Added rf_amp field
* ui_transmitter : Added color grading depending on gain settings
* Removed TransmitterModel::set_rf_amp(bool) call from every apps loading ui_transmit
* transmitter_model : RF_amp disabled by default
* APRS Tx app : Fixed frequency keypad not showing up
* Morse Tx app : Removed TransmitterModel::set_lna() and TransmitterModel::set_vga() calls
Re-enabled the tone key selector in Soundboard
Soundboard now uses OutputStream, like Replay
Constexpr'd a bunch of consts which were going to BSS section
Exiting an app now goes back to main menu
Cleaned up Message array
